What are the causes of hypoglycemia (low blood sugar)?

From the Guidelines

Hypoglycemia is primarily caused by medication-related factors, particularly insulin and other glucose-lowering medications, as well as errors in insulin dosing and administration, which can lead to a significant reduction in blood sugar levels. According to a recent study published in 2024 1, common preventable sources of iatrogenic hypoglycemia include improper prescribing of other glucose-lowering medications and inappropriate management and follow-up of the first episode of hypoglycemia.

Some of the key factors that contribute to hypoglycemia include:

• Insulin dosing errors, missed doses, and administration errors, including incorrect insulin type and timing of dose 1
• Improper prescribing of other glucose-lowering medications 1
• Inappropriate management and follow-up of the first episode of hypoglycemia 1
• Kidney failure, which is an important risk factor for hypoglycemia in the hospital, possibly due to decreased insulin clearance 1
• Sudden reduction of corticosteroid dose, reduced oral intake, emesis, and inappropriate timing of short- or rapid-acting insulin doses in relation to meals 1

Recent studies have shown that the use of continuous glucose monitoring (CGM) and automated insulin delivery (AID) devices can help mitigate hypoglycemia by providing an early warning system for impending hypoglycemia 1. The use of personal CGM and AID devices, such as insulin pumps, is recommended to help prevent and manage hypoglycemia. Additionally, bundled preventive therapies, including proactive surveillance of glycemic outliers and an interdisciplinary data-driven approach to glycemic management, have been shown to reduce hypoglycemic episodes in the hospital by 56-80% 1.

From the FDA Drug Label

The risk of hypoglycemia after an injection is related to the duration of action of the insulin and, in general, is highest when the glucose lowering effect of the insulin is maximal Other factors which may increase the risk of hypoglycemia include changes in meal pattern (e.g., macronutrient content or timing of meals), changes in level of physical activity, or changes to concomitant drugs Patients with renal or hepatic impairment may be at higher risk of hypoglycemia

The causes of hypoglycemia (low blood sugar) include:

• Changes in insulin regimen: such as changes in insulin strength, manufacturer, type, injection site, or method of administration
• Changes in meal pattern: such as changes in macronutrient content or timing of meals
• Changes in level of physical activity
• Changes to concomitant drugs
• Renal or hepatic impairment: patients with these conditions may be at higher risk of hypoglycemia
• Medication errors: such as accidental mix-ups among insulin products 2

From the Research

Causes of Hypoglycemia

The causes of hypoglycemia (low blood sugar) can be categorized into several factors, including:

• Medications: Glucose-lowering medications such as insulin and sulfonylurea therapy can increase the risk of hypoglycemia 3, 4, 5
• Lifestyle factors: Delayed or missed meals, physical exercise, and drug or alcohol consumption can contribute to hypoglycemia 3, 4
• Medical conditions: Certain medical conditions, such as renal dysfunction, hypoglycemia unawareness, and cognitive dysfunction, can increase the risk of hypoglycemia 3
• Other factors: Age, duration of diabetes, and concomitant medication can also contribute to the development of hypoglycemia 3, 4

Drug-Induced Hypoglycemia

Drugs can also cause hypoglycemia, including:

• Antidiabetic agents: These can stimulate insulin release, reduce insulin clearance, or interfere with glucose metabolism 6
• Non-antidiabetic agents: Certain drugs, such as NSAIDs, analgesics, antibacterials, antimalarials, antiarrhythmics, and antidepressants, can also induce hypoglycemia 6

Rare Causes of Hypoglycemia

Rare causes of hypoglycemia in adults include:

• Genetic causes: Endogenous hyperinsulinism and inborn errors of metabolism (IEM) can cause hypoglycemia 7
• Paraneoplastic causes: Non-Islet-Cell Tumour Hypoglycemia (NICTH) and ectopic insulin secretion can cause hypoglycemia 7
• Autoimmune causes: Antibodies against insulin or the insulin receptor can cause hypoglycemia 7
• Other rare causes: Cortisol insufficiency, insulinoma, bariatric or gastric surgery, pancreas transplantation, and glucagon deficiency can also cause hypoglycemia 7